Add image upload preview functionality; update titles and templates for consistency

Co-authored-by: Copilot <copilot@github.com>

frontend/app/templates/generate_image.html

@@ -1,9 +1,9 @@
 {% extends "base.html" %}
-{% block title %}Image Generation — AI Allucanget{% endblock %}
+{% block title %}Image Generation — All You Can GET AI{% endblock %}
 {% block content %}
 <div class="card">
   <h1>Image Generation</h1>
-  <form method="post">
+  <form method="post" enctype="multipart/form-data">
     <label for="model">Model</label>
     <input id="model" name="model" type="text" required
            placeholder="e.g. openai/dall-e-3"
@@ -49,6 +49,21 @@
       <option value="4" {% if request.form.get('n')=='4' %}selected{% endif %}>4</option>
     </select>
 
+    <label for="reference_image">Reference image (optional)</label>
+    <input
+      id="reference_image"
+      name="reference_image"
+      type="file"
+      accept="image/png,image/jpeg,image/webp,image/gif"
+    >
+    <p class="text-muted mt-1" id="reference-image-help">
+      Upload image for visual reference in upcoming image-to-image flow.
+    </p>
+    <div class="image-upload-preview" id="image-upload-preview" hidden>
+      <p class="text-muted" id="image-upload-filename"></p>
+      <img id="image-upload-preview-img" alt="Uploaded reference image preview" class="generated-image">
+    </div>
+
     <button type="submit">Generate image</button>
   </form>